We propose to pursue our findings of raised noradrenaline in hypertensive patients with increased levels of anxiety, depression, and suppressed anger by attempting to determine whether noradrenergic tone and blood pressure can be reduced by an intensive relaxation therapy method. We wish to explore whether pre-therapy psychological and neural profiles can aid in predicting responses to relaxation. Patients with mild primary hypertension (90-105 mmHg diastolic) will undergo psychobehavioral evaluation to include scales of depression, anxiety, anger, hostility, and drive. Self-administered questionnaires will be validated by objective evaluation. We will use ultrasound systolic time intervals and plethysmography to measure cardiac function and vascular resistance. We will measure contents of plasma catecholamines and metabolites in the basal state and their responses after stress. During role instigated mental stress we will use automated ambulatory blood pressure and blood withdrawal systems. An improved experimental paradigm "articulated thoughts to simulated situations" will be applied for detecting cognitions in complex interpersonal situations that reflect ongoing thought process. Patients will be randomized to undergo either intensive relaxation therapy on site and later at home utilizing tapes or to a control group to receive information about relaxation techniques and other hygienic measures. We will test the hypothesis that noradrenergic activity is increased in some patients with primary hypertension and is a pathogenic factor initiating and maintaining their blood pressure elevation. We will also test the corollary that behavioral patterns related to anxiety and suppressed anger are associated with noradrenergic hyperactivity. An important test of the linking will be whether relaxation therapy is more successful in lowering tone and pressure in patients with high levels of pre-therapy neural tone. Responses of cardiac correlates of tone will be compared with blood pressure responses before and at intervals after relaxation therapy. In addition to aiding in the elucidation of the pathophysiology of primary hypertension, finding predictive psychological and neural features may be of clinical value in the selection of rational therapy for patients with primary hypertension.